Sprint warned customers to be on the lookout for suspicious activity after hackers gained access to an unspecified number of user accounts through a Samsung website.

In a statement to Mobile World Live (MWL), Sprint said it was notified of the breach on 22 June, alerted customers who may have been affected and reset their account PINs. It did not say how many accounts were involved or how long the hackers had access.

ZDNet reported the attackers may have viewed personal information including customers’ name, billing address, phone number, device type and ID, monthly charges, account number and subscriber ID.

However, Sprint told MWL other sensitive information including “credit card and social security numbers are encrypted and were not compromised”.

Sprint added it takes matters involving customer privacy “very seriously” and has established a dedicated customer care team to help users with issues related to the incident.

The breach is the second Sprint suffered this year: the operator’s Boost Mobile prepaid brand was the target of an attack in March.

In August 2018, proposed merger partner T-Mobile US also experienced a data breach, which affected an estimated 2.3 million customers.